Create database schema with terraform - database

Question

I created RDS instance using aws_db_instance (main.tf):
resource "aws_db_instance" "default" {
identifier = "${module.config.database["db_inst_name"]}"
allocated_storage = 20
storage_type = "gp2"
engine = "mysql"
engine_version = "5.7"
instance_class = "db.t3.micro"
name = "${module.config.database["db_name_prefix"]}${terraform.workspace}"
username = "${module.config.database["db_username"]}"
password = "${module.config.database["db_password"]}"
parameter_group_name = "default.mysql5.7"
skip_final_snapshot = true
}
Can I also create database schemas from file schema.sql with terraform apply?
$ tree -L 1
.
├── main.tf
└── schema.sql

Answer 1

You can use a provisioner (https://www.terraform.io/docs/provisioners/index.html) for that:
resource "aws_db_instance" "default" {
identifier = module.config.database["db_inst_name"]
allocated_storage = 20
storage_type = "gp2"
engine = "mysql"
engine_version = "5.7"
instance_class = "db.t3.micro"
name = "${module.config.database["db_name_prefix"]}${terraform.workspace}"
username = module.config.database["db_username"]
password = module.config.database["db_password"]
parameter_group_name = "default.mysql5.7"
skip_final_snapshot = true
provisioner "local-exec" {
command = "mysql --host=${self.address} --port=${self.port} --user=${self.username} --password=${self.password} < ./schema.sql"
}
}
#Apply scheme by using bastion host
resource "aws_db_instance" "default_bastion" {
identifier = module.config.database["db_inst_name"]
allocated_storage = 20
storage_type = "gp2"
engine = "mysql"
engine_version = "5.7"
instance_class = "db.t3.micro"
name = "${module.config.database["db_name_prefix"]}${terraform.workspace}"
username = module.config.database["db_username"]
password = module.config.database["db_password"]
parameter_group_name = "default.mysql5.7"
skip_final_snapshot = true
provisioner "file" {
connection {
user = "ec2-user"
host = "bastion.example.com"
private_key = file("~/.ssh/ec2_cert.pem")
}
source = "./schema.sql"
destination = "~"
}
provisioner "remote-exec" {
connection {
user = "ec2-user"
host = "bastion.example.com"
private_key = file("~/.ssh/ec2_cert.pem")
}
command = "mysql --host=${self.address} --port=${self.port} --user=${self.username} --password=${self.password} < ~/schema.sql"
}
}
mysql client needs to be installed on your device.
If you don't have direct access to your DB, there is also a remote-exec provisioner, where you can use a bastion host (transfer file to remote place with file provisioner first).
If your schema is not to complex, you could also use the MySQL provider of terraform:
https://www.terraform.io/docs/providers/mysql/index.html